Sabatier principle guiding the design of cathode catalysts for Li-CO2 batteries

Abstract

The Sabatier principle has been widely used for designing electrocatalysts for energy conversion applications, but it is rarely mentioned in the research of cathode catalyst of Li-CO2 batteries. In our work, the “volcanic” relationship between the catalytic activity and the adsorption energy of the catalyst to the intermediates is first demonstrated based on the first-principles calculation, which meets the Sabatier principle and can be used to design the cathode catalysts. The increases in the number of nitrogen-vacancy in WN shift the d-band center and increase the interaction with the reactants. The catalytic activity increases first and then decreases with the increase of adsorption energy, which was proved in the experiment. The optimal catalyst for moderate adsorption of intermediate makes the thin Li2CO3 distribute evenly. It exhibits a median voltage difference of 0.68 V and an energy efficiency of 84.33% at 20 μA cm−2 with a limited capacity of 200 μA h cm−2.